[Haskell-cafe] GHC optimisations

[Isaac Dupree]

Simon Peyton-Jones wrote:
> | Something I've pondered is adding a more-expressive form of RULES which
> | works using general pattern matching:
> 
> Yes, but it would need the rule-matcher in the Simplifier to be more sophisticated.  Have a look in specialise/Rules.lhs.
> 
> No need to be so ambitious; just moving towards what you can do in PrelRules would be an improvement

Careful about concealing
http://hackage.haskell.org/trac/ghc/ticket/1603 even more than it 
already is! (Not actually, but it would probably be even harder to track 
down and still be a bug in some really obscure cases.  Maybe there's a 
flag to disable PrelRules-optimizations for a run of ghc.)

Isaac